Make HConstant::InstanceOf less ambiguous.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index a4c54e761e731944247005f0b940df7804617206..f7adb603c1f6e18a21be067f2ac38f3049b83fcb 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -2866,7 +2866,8 @@ HCheckMaps* HCheckMaps::New(Zone* zone,
   check_map->Add(map, zone);
   if (map->CanOmitMapChecks() &&
       value->IsConstant() &&
-      HConstant::cast(value)->InstanceOf(map)) {
+      map->CanTransition() &&

[Toon Verwaest, 2013/08/14 17:48:24]

For the record, we should also be able to omit map-checks for non-transitioning
objects, since those maps are always stable. We should just not install a
dependency.

[Michael Starzinger, 2013/08/16 08:22:51]

Done. Addressed this comment right away.

+      HConstant::cast(value)->HasMap(map)) {
     check_map->omit(info);
   }
   return check_map;